Reflecting-lamp



` H. A. DOUGLAS.

REFLECTING LAMP.

APPLlcATloN FILED4 APRA. 19u.

Patented Oct. 26, 1'920.

UNITED STATES HARRY A. DOUGLAS, OF BRONSON, MICHIGAN.

REFLECTING-LAMP.

. Application filed April 4,

To all whom/t may concern.'

Be it known that I, HARRY A; DOUGLAS, citizen of the United States, residing 'at Bronson, in the county of Branch and State of Michigan, have invented a certain new and useful Improvement in Reflecting- Lamps, of which the following is a full, clear, concise, and exact description;

y invention relates to reflecting electric lamps and relates particularly to an electric lamp employing a concave casing, a concave reflector therein and spaced apart therefrom' at its rear end, and a tubular holder assembled at its front end with the reflector and at its rear end with the casing. The invention has for its object the prof vision of an improved and simplified construction in this type of electric lamp whereby the lamp bulb may readily be focused with respect to the reflector without requiring any other than the mere longitudinal movement of the lamp bulb.

I will explain my invention more fully by reference to the accompanying drawing showing the preferred embodiment of the invention and inwhich Figure 1 is-a view in elevation, partially in section, illustrating the construction of my invention; Fig. 2 is a longitudinal sectional View of a part of the structure.; Fig. 3 is an end view of the .Structure shown in Fig. 2; Fig. 4 is a-view on a larger scale of a part of the structure as it appears in Fig.\1, the tubular holder being, however, shown in section; Fig. 5 is a view on line 5 5 of Fig. 4; and Fig. 6 is a view on line 6-6 of Fig. 4.

Like parts are indicated by similar characters of reference throughout the different figures.

The concave reflector 1 is received in the concave reflector carrying casing 2 and is spaced apart therefrom. A rearwardly extending tubular continuation 3 virtually constitutes a continuation of lthe reflector l. The front end of the tubular holder is provided with a flange 31. In the form, of the invention shown, the rearv end of the holder is provided with a flange 32 that is preferably in the'form of a nut in threaded engagement with the complemental portion of the holder. Thereflector and casing are disposed between these flanges and the pressure with which the flanges en- 4. gage these elements is regulated by the nut y32. The` holder 3 extends from the reflector to the casing andJis assembled at one end Specification ofy Letters Patent.

n Patented Oct. 26, 1920. 1917. serial No.A 159,731.

with the reflectorand at the other end with the casing and serves to prevent these parts from changing their relative positions whereby any focalK adjustment-of the lamp bulb is prevented from being disturbed; A spring tongue 4 is integrally formed with ashell 5 that constitutes a holder for contact carriers, this spring tongue having ample clearance at its side margins to permit it freely to function. Some part of the tongue, preferably the rear free end thereof, has a part 6 projecting therefrom which is narrower than the balance, of the tongue and is slightlynarrower thanva slot 7 in the holder 3 whereby this portion may project into the slot to prevent, the shell from turning with respect to the slot while at the same time the side margins of the tongue 4 are adapted to press against the side margins of the slot 7. The tongue thus presses upon a surface of the holder 3 `and, where there is but one tongue, forces the shell toward the opposite side of the holder whereby the shell is held in engagement with the .holder 3. The slot the shell 5 may be moved back and forth in its holder 3 whereby in the structure illustrated the position of the llamp bulb 8 which is carried by the forward end of the shell in front of the reflector may be adjusted with respect to the reflector. The base 9 of the lamp bulb 8 constitutes the forward Contact carrier and as the arrangement illustrated is a double pole arrangement this contact carrier 9 carries two rear contacts 10 and'11. The lamp base-9 is provided with bayonet pins 12 engageable within bayonet seats 13 constituting parts of bayonet slots 14.

The rear contact carrier includes a plug 15 of insulation, this plug being in fXed relation to the shell or lamp plug 15 carries two metallic spring barrels k16 which house springs 17. These ksprings push the front contacts 18 and 19 into en-J gagement with the contacts 10 and 11 and push the rear contacts 20 and 21 into engagement with the terminal plugs 22 and 23 that are inserted through lateral openings 24 in the plug 15.

The focusing device includes one member 26 that is in substantially fixed connection with the shell 5 stantially fixedy connection with the plug 15 that is, in turn in substantially fined connection with said shell. The complementar preferably by beingin sub-i bulb holder 5. The

8o 7 is elongated so that is carriedrupon the member 27 of the focusing .device is carried by the holder 3;.this member 27 being rotatable and in threaded connection with the 'slot 3l by which the sleeve may be turned and as the sleeve is prevented from moving back and forth the rod 26 must move back and forth when this sleeve is turned to cause corresponding movement of the shell 5 and the lamp bulb 8 carried att-he forward end of this shell. The spring Ll acts to hold the shell 5in any position to which it is moved and serves to prevent the sleeve`27 from accidentally rotating to cause accidental misadjustment of the lamp bulb. p

From the foregoing it has 'been made clear that the construction of my invention includes an electric lamp bulb mounted to slide within and independently of the tubular holder 3 to be movable in and out for focusing, in combination with an adjusting device for moving the lamp bulb in and out and including one member movable longitudinally and independently of said holder and connected with the lamp bulb. and another member co-acting with and movable with respect member and, thereby,

to the rear end wall of said holder to effect longitudinal movement of the .aforesaid of the lamp bulb, whereby no rotary movement need be imparted to the lampbulb in effecting focal adjustment and whereby the mechanism for effecting the focal adjustment is much simplified.`

While I have herein shown and particu- 'and casing normally to larly described the lpreferred embodiment of my invention I do not wish to be limited to the precise details of construction shown, as changes may readily bemade without departing from the spirit of my invention, but having thus described my invention I claim as new and desire to secure by Letters Patent the following In a reflecting lamp, the combination with a concave casing; of a concave reflector therein and Vspaced apart therefrom at its rear, said casing and reiector having openings at their rear ends; a tubular holder eX- tending from the reflector to the casing and assembled at said openings with the reflector have no motion with respect thereto, said holder having a rear end wall; an electric lamp bulb; a shell at the forward end of said tubular holder and with whose forward end said lamp bulb is assembled, said shell being within and longitudinally of said holder to be movable in and out for focusing the lamp; a plug connected with the rear end of said shell and movable therewith longitudinally of said holder, this plug carrying forwardly pressed contacting means engageable with contacting means upon the base of the lamp bulb Jto include the lighting element of the bulb in circuit; a rod carried by and extending rearwardly from the plug; and a sleeve in threaded engagement with the rod and confined to a single plane of rotation by the rearend wall of said tubular holder whereby the contact carrying plug, the shell with which the plug is connected, and the lamp bulb'oonnected with the shell are together movable longitudinally of the tubular holder to focus the lamp.

kIn witness whereof, I hereunto subscribe my name this 28th day of February, A. D.,

HARRY A. DOUGLAS.

mounted to slide 

